1. Field of the Invention
The present invention relates to a light-emitting tube array display device, and more particularly to a light-emitting tube array display device for displaying optional images, in which are arranged in parallel a plurality of light-emitting tubes (also referred to as xe2x80x9cdisplay tubesxe2x80x9d or xe2x80x9cgas discharge tubesxe2x80x9d) comprising narrow tubes of a diameter of approximately 0.5 to 5 mm having a phosphor layer disposed and discharge gas filled inside.
2. Description of Related Art
As such a display device described above, a display device described in, for example, Japanese Unexamined Patent Publication No. 2000-315460 is known. In such display devices, a plurality of light-emitting points are formed in a longitudinal direction of light-emitting tubes by, for example, forming a plurality of electrodes on a substrate supporting the light-emitting tubes, bringing an electrode-formed surface of the substrate into contact with the light-emitting tubes, and applying voltage to the electrodes.
In such display devices, for forming the electrodes on the substrate on the front side (display surface side), a transparent electro-conductive film of, for example, ITO is formed for transmitting light emitted from the light-emitting tubes. However, since the transparent electro-conductive film is high-resistant, the sole use thereof causes a voltage drop and a stable discharge characteristic can not be obtained. For this reason, a hybrid electrode which is a combination of a transparent electro-conductive film and a metal bus electrode has been used often until now.
However, in order to form such a hybrid electrode, steps of forming a film, patterning by a photolithography, and etching need to be repeated twice. Thus, many steps are required for forming such a hybrid electrode.
Besides, since the transparent electro-conductive film has poor ductility, the film may break as the substrate bends when the film is formed on a flexible PET (polyethylene terephthalate) substrate or the like.
Accordingly, there has been a demand for a flexible electrode which can be formed with a simple process and which is capable of following bending of the substrate.
The present invention has been made in view of these circumstances and an object thereof is to prevent breaking of electrodes caused by bending of a substrate and to improve the efficiency of taking out light emitted from light-emitting tubes, by forming the electrodes of a metal film having a mesh pattern, a ladder pattern or a comb-shape pattern.
The present invention provides a light-emitting tube array display device comprising: a light-emitting tube array constituted of a plurality of light-emitting tubes arranged in parallel, each of the light-emitting tubes consisting of narrow tube having a phosphor layer disposed and discharge gas filled inside; a flexible sheet for flatly supporting the light-emitting tube array and deforming the light emitting tube array in a direction perpendicular to a longitudinal direction of the light-emitting tubes; and a plurality of electrodes formed on a face of the flexible sheet opposed to the light-emitting tubes, for generating discharge inside the light-emitting tubes by an application of voltage, the electrodes each being formed of a metal film having a mesh pattern, a ladder pattern or a comb-shape pattern.
According to the present invention, the electrodes do not break even when the flexible sheet is deformed (bended) in the direction perpendicular to the longitudinal direction of the light-emitting tubes, since the electrodes comprise the metal film, of the mesh pattern, the ladder pattern or the comb-shape pattern having a plurality of openings through which light can be transmitted. Further, in discharge inside the light-emitting tubes, the present invention can improve the efficiency of taking out light emitted from the light-emitting tubes while maintaining a discharge characteristic similar to that when a transparent electrode of, for example, ITO or the like is used.
The following is a description of the present invention according to embodiments shown in figures. However, it should be understood that the present invention is not limited thereto and various modifications can be made.